personally, i love breloom, its more convenient for me than poison heal gliscor, but not in this case. i know its obvious that it has a double weakness to flying, and i know keldeo could use icy wind, but the pony also has that weakness, potentially crippling your team. i personally would replace it with poison heal gliscor.
Trait: Poison Heal
EV's 252 HP/252 Def/4 Spd